Chuck table and method for manufacturing chuck table

Abstract

To manufacture in a short time a chuck table for sucking and holding at least two works of different areas or shapes.SOLUTION: A chuck table (10) capable of switching a shape of a suction surface for sucking and holding at least each of two work pieces of different areas or shapes, comprises: a first porous member (30) having a first holding surface (32); a second porous member (31) having a second holding surface (33); a glass member (38) disposed between the first porous member and the second porous member; and a frame body (11) having a recess (12) for accommodating the first porous member, the second porous member, and the glass member; wherein the first porous member, the second porous member, and the frame are bonded to each other by an adhesive member (36).SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a chuck table and a method for manufacturing the chuck table.

Background Art

[0002] In a processing apparatus that performs predetermined processing on a wafer, such as a grinding apparatus that grinds a wafer with a grinding wheel or a polishing apparatus that polishes a wafer with a polishing pad, the processing is performed while the wafer is held on the holding surface of a chuck table. The chuck table is configured by holding a porous member made of a porous material in a frame body, and by sucking air from the porous member with a suction source, a suction force is applied to the holding surface (the upper surface of the porous member) to suck and hold the wafer.

[0003] As disclosed in Patent Documents 1, 2, and 3, a chuck table having a configuration in which a barrier is disposed to partition the holding surface (porous portion) is known in order to be able to suck and hold at least two types of wafers having different shapes. Such a chuck table with a partitioned holding surface is called a universal chuck table or the like.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] Conventional universal chuck tables had a problem in that the number of parts for partitioning the holding surface increased, resulting in longer manufacturing times. For example, in a universal chuck table that divides the holding surface into two regions, a first porous member, a barrier member, and a second porous member are accommodated and adhered in a recess of a frame body. Therefore, compared to a general chuck table in which one porous member is accommodated and adhered in a recess of a frame body, the manufacturing of the universal chuck table took much more time.

[0006] Therefore, there is a problem to be solved of manufacturing a chuck table that suction-holds at least two workpieces with different areas or shapes in a short time.

Means for Solving the Problem

[0007] One aspect of the present invention is a chuck table capable of switching the shape of a suction surface for suction-holding at least two workpieces with different areas or shapes respectively, including a first porous member having a first holding surface, a second porous member having a second holding surface, a glass member disposed between the first porous member and the second porous member, and a frame body having a recess for accommodating the first porous member, the second porous member, and the glass member, and the first porous member, the second porous member, and the frame body are adhered with an adhesive member.

[0008] It is preferable that the glass member and the adhesive member are formed of the same member.

[0009] One aspect of the present invention is a method for manufacturing a chuck table capable of switching the shape of a suction surface to suction-hold at least two workpieces having different areas or shapes, the method including: disposing an upper surface of a porous plate in a recess of a frame body in an exposed state; applying a first glass paste to an inner surface of the recess and an outer surface of the porous plate; heating at a first temperature to bond the frame body and the porous plate in an adhesion step; after the adhesion step, forming a groove reaching from the upper surface of the porous plate to a bottom surface of the recess in a groove forming step; filling the groove with a second glass paste in a filling step; heating the second glass paste at a second temperature lower than the first temperature to cure the second glass paste and form a glass member in a curing step; and grinding the upper surface with a grinding stone to form the suction surface in a grinding step.

[0010] It is preferable that the first glass paste and the second glass paste are the same member.

[0011] Granular aggregate may be added to the second glass paste so that the grinding load is the same when grinding the cured second glass paste and the porous plate with a grinding stone.

Advantages of the Invention

[0012] According to the chuck table and the method for manufacturing the same of the present invention, a chuck table for suction-holding at least two workpieces having different areas or shapes can be manufactured in a short time.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0014] Hereinafter, with reference to the accompanying drawings, the chuck table of the present embodiment and its manufacturing method will be described. Specifically, it relates to a chuck table whose suction surface shape can be switched in order to suck and hold at least two workpieces having different areas or shapes, and a manufacturing method thereof.

[0015] As shown in FIG. 1, the chuck table 10 of the present embodiment is formed by attaching a porous plate 13 of a porous material inside a recess 12 provided in the upper part of a frame body 11. FIG. 1 shows a state before the frame body 11 and the porous plate 13 are combined. The frame body 11 has a disk-shaped base 15 and an annular protruding portion 16 protruding from the upper surface of the base 15, and a recess 12 capable of accommodating the porous plate 13 is formed inside the protruding portion 16.

[0016] The inner surface of the recess 12 has a flat bottom surface 17 located inside the protruding portion 16 and a cylindrical side surface 18 formed by the inner peripheral surface of the protruding portion 16. The upper part of the recess 12 is open, and the porous plate 13 can be accommodated inside the recess 12 from above. A plurality of holes 19 are formed in the base 15 outside the recess 12. The holes 19 are used when attaching the chuck table 10 to a grinding device 40 (FIG. 9) described later.

[0017] In the recess 12 of the frame body 11, a first suction hole 20 is formed at approximately the center of the bottom surface 17, and a plurality of second suction holes 21 are formed at intermediate positions in the radial direction of the bottom surface 17. The plurality of second suction holes 21 are each arranged at a substantially equal distance from the first suction hole 20 and are positioned differently in the circumferential direction centered on the first suction hole 20. Further, an annular suction groove 22 is formed on the bottom surface 17 at a position overlapping the plurality of second suction holes 21. As shown in FIGS. 3, 5, 7, and 8, inside the frame body 11, a first suction passage 23 communicating with the first suction hole 20 and a second suction passage 24 communicating with the second suction holes 21 and the suction groove 22 are formed, and the first suction passage 23 and the second suction passage 24 each open to the bottom surface of the base 15.

[0018] The porous plate 13 is made of a porous material such as ceramics having a large number of pores inside and has a disc shape that fits into the recess 12 of the frame body 11. The upper surface of the porous plate 13 constitutes a suction surface 25 for sucking and holding the workpiece. Further, the porous plate 13 has a flat lower surface 26 that can be placed on the bottom surface 17 of the recess 12 and a cylindrical outer peripheral surface 27 that faces the side surface 18 of the recess 12. The diameter (outer diameter) of the outer peripheral surface 27 of the porous plate 13 is substantially the same as the diameter (inner diameter) of the side surface 18 of the recess 12.

[0019] After preparing the frame body 11 and the porous plate 13 having the above configuration, the chuck table 10 is manufactured. Each step of the manufacturing method of the chuck table 10 will be described below.

[0020] [Adhesion step] First, perform the bonding process shown in FIGS. 2 and 3. In the bonding process, the upper surface (suction surface 25) of the porous plate 13 is placed in the concave portion 12 of the frame body 11 in an exposed state, and the frame body 11 and the porous plate 13 are bonded together using the first glass paste 35 shown in FIG. 3. In FIG. 3, the first glass paste 35 is shown by a dashed line, but it does not mean that the first glass paste 35 is sparsely arranged. The first glass paste 35 is applied to the entire surface of the region of the inner surface of the concave portion 12 excluding the first suction hole 20, the second suction hole 21, and the suction groove 22. The application of the first glass paste 35 may be performed manually by an operator or using an application device.

[0021] The first glass paste 35 is obtained by adding a vehicle such as an organic solvent or a resin to glass powder (glass frit), kneading them, and forming them into a paste. At room temperature, it is in a paste state with a predetermined viscosity. In this embodiment, the glass powder contained in the first glass paste 35 is made of glass with a softening point of 800 ° C and a melting point of 1000 ° C, and the particle size is 40 μm to 60 μm.

[0022] Apply the first glass paste 35 to the inner surface of the concave portion 12 and the outer surface of the porous plate 13. Regarding the inner surface of the concave portion 12, the region of the bottom surface 17 excluding the first suction hole 20, the second suction hole 21, and the suction groove 22 and the entire surface of the side surface 18 are the regions to which the first glass paste 35 is applied. Regarding the outer surface of the porous plate 13, the lower surface 26 and the outer peripheral surface 27 are the regions to which the first glass paste 35 is applied.

[0023] With the first glass paste 35 applied, a porous plate 13 is placed inside the recess 12. As shown in FIG. 3, the lower surface 26 of the porous plate 13 is held on the bottom surface 17 of the recess 12 via the first glass paste 35, and the outer peripheral surface 27 of the porous plate 13 is held on the side surface 18 of the recess 12 via the first glass paste 35. In other words, the porous plate 13 is held inside the recess 12 in a state where the first glass paste 35 is filled between the inner surface of the recess 12 and the outer surface of the porous plate 13. And, at locations other than the first suction holes 20, the second suction holes 21, and the suction grooves 22, which are regions for intake air, the recess 12 and the porous plate 13 can be brought into complete contact with each other.

[0024] Subsequently, the chuck table 10 with the first glass paste 35 filled between the inner surface of the recess 12 and the outer surface of the porous plate 13 is heated at the first temperature. When heating the chuck table 10, the chuck table 10 is transported to a heating device (not shown) having a heating chamber large enough to accommodate the chuck table 10, and the chuck table 10 is installed in the heating chamber. Then, the periphery of the chuck table 10 in the heating chamber is heated to the first temperature.

[0025] The first temperature is a temperature equal to or higher than the softening point and lower than the melting point of the glass powder contained in the first glass paste 35. In the present embodiment, the first temperature is set to a temperature (950 °C) slightly lower than the melting point of the glass powder contained in the first glass paste 35. As a result of heating at the first temperature, the glass powder of the first glass paste 35 becomes in a state of being welded to each of the frame body 11 and the porous plate 13. And when the heating at the first temperature is completed and the temperature of the first glass paste 35 drops, it becomes an adhesive member 36 (see FIGS. 3 and 5) in which the first glass paste 35 is solidified, and the frame body 11 and the porous plate 13 are adhered by the adhesive member 36.

[0026] [Groove forming step] After the bonding step, the groove forming step is performed. When performing the groove forming step, the chuck table 10 is taken out from the heating device, and the chuck table 10 is transported to a cutting device (not shown) equipped with a cutting tool.

[0027] As shown in FIGS. 4 and 5, in the groove forming step, a groove 28 is formed in the porous plate 13. The chuck table 10 is held on the holding table of the cutting device, and cutting is performed from the upper surface to the lower surface 26 of the porous plate 13 by a cutting tool to form the groove 28. The groove 28 is formed so as to penetrate from the upper surface to the lower surface 26 of the porous plate 13 and reach the bottom surface 17 of the recess 12. When forming the groove 28, the adhesive member 36 directly below the groove 28 may be removed together with the porous plate 13, or the adhesive member 36 directly below the groove 28 may be left without being removed.

[0028] The shape of the groove 28 is set according to the shape and size of a desired workpiece held by the chuck table 10. The groove 28 in the present embodiment is annular and concentric with the outer peripheral surface 27 of the porous plate 13, and is located between the first suction hole 20 and the suction groove 22 in the recess 12.

[0029] By forming the groove 28 in an annular shape, the porous plate 13 is divided into two, and a central first porous member 30 and an outer second porous member 31 are formed. The first porous member 30 is a circular porous member located above the first suction hole 20. The second porous member 31 is an annular porous member located above the second suction hole 21 and the suction groove 22. The suction surface 25 of the porous plate 13 is divided into a first holding surface 32 which is the upper surface of the first porous member 30 and a second holding surface 33 which is the upper surface of the second porous member 31 with the groove 28 interposed therebetween.

[0030] [Filling step] After the groove forming step, a filling step is performed. As shown in FIGS. 6 and 7, in the filling step, the groove 28 is filled with a second glass paste 37. The filling of the second glass paste 37 may be performed manually by an operator or may be performed using a supply device such as a dispenser. As shown in FIG. 7, a sufficient amount of the second glass paste 37 is supplied so that no voids are formed inside the groove 28. For example, an amount of the second glass paste 37 that slightly bulges is supplied to the suction surface 25 of the porous plate 13.

[0031] The second glass paste 37 is obtained by adding a vehicle such as an organic solvent or a resin to glass powder (glass frit), kneading them, and forming a paste. At room temperature, it is in a paste state with a predetermined viscosity. In the present embodiment, the first glass paste 35 and the second glass paste 37 are the same member (same material). That is, the glass powder contained in the second glass paste 37 is made of glass with a softening point of 800°C and a melting point of 1000°C, and the particle size is 40 μm to 60 μm. Also, the vehicles contained in the first glass paste 35 and the second glass paste 37 are of the same material.

[0032] [Curing process] After the filling process, a curing process is performed. The curing process will be described with reference to FIGS. 6 and 7 in the same manner as the previous filling process. In the curing process, the chuck table 10 filled with the second glass paste 37 in the groove 28 is heated at a second temperature. When heating the chuck table 10, the chuck table 10 is housed in a heating chamber of a heating device (not shown), and the periphery of the chuck table 10 in the heating chamber is heated to the second temperature.

[0033] The second temperature is lower than the first temperature at which the first glass paste 35 was heated in the previous adhesion process, and it is the temperature at which the glass powder contained in the second glass paste 37, which is the same member (same material) as the first glass paste 35, is melted. In the present embodiment, the second temperature is set to the softening point (800°C) of the glass powder contained in the second glass paste 37.

[0034] The second glass paste 37 heated at the second temperature causes the glass powder to temporarily melt inside the groove 28 and the whole to become softened. When the heating is completed and the temperature of the second glass paste 37 is lowered to room temperature, the second glass paste 37 solidifies and changes into a hard glass member 38 (see FIGS. 6 to 8). As a result, the first porous member 30 and the second porous member 31 are partitioned from each other via the hardened glass member 38. That is, the second glass paste 37 has the glass powder melted and adhered by heating and solidifies by cooling to room temperature. In this way, the glass member 38 serves as an airtight barrier to block air from passing between the first porous member 30 and the second porous member 31.

[0035] The hardened glass member 38 becomes transparent or white. Also, the first glass paste 35 injected as an adhesive between the frame body 11 and the porous plate 13 may be solidified and a transparent or white glass member may be arranged. Note that the glass member 38 can be colored other than transparent and white.

[0036] When using the transparent glass member 38, for example, a UV light source is arranged on the chuck table 10, and the ultraviolet rays transmitted through the glass member 38 are irradiated onto a wafer (workpiece) held on the holding surface of the chuck table 10 to cure an ultraviolet curable resin applied to the wafer.

[0037] Also, when using the white glass member 38, for example, when the holding surface of the chuck table 10 holds a wafer (workpiece), the amount of the white glass member 38 protruding outside the wafer is imaged by a camera to determine whether the center of the holding surface and the center of the wafer coincide. Since black and white are distinct in the captured image, it is useful.

[0038] [Grinding process] Through the previous adhesion process, groove formation process, filling process, and hardening process, the porous plate 13 is divided into a first porous member 30 and a second porous member 31, and a glass member 38 (formed by curing the second glass paste 37) is formed between the first porous member 30 and the second porous member 31. Therefore, the upper surface of the porous plate 13 is configured such that the upper surface of the glass member 38 is positioned between the first holding surface 32 and the second holding surface 33. Since the upper surface of the glass member 38, the first holding surface 32, and the second holding surface 33 are often not on the same plane with respect to the upper surface of the frame body 11 (the upper edge of the protruding portion 16), in order to make these into a smooth and identical plane, the grinding process shown in FIG. 8 is performed. Although the adhesive member 36 is not shown in FIG. 8, the adhesive member 36 is present on the chuck table 10 also in the grinding process.

[0039] The grinding process is performed by installing the chuck table 10 on the grinding device 40 shown in FIG. 9. The X-axis direction, Y-axis direction, and Z-axis direction in the grinding device 40 are in a mutually perpendicular relationship. The X-axis direction and the Y-axis direction are substantially horizontal directions, and the Z-axis direction is the vertical direction.

[0040] The grinding device 40 has a rectangular opening 42 extending in the Y-axis direction on the upper surface of the device base 41. The opening 42 is covered by a moving plate 43 and a bellows-shaped waterproof cover 44.

[0041] A table base 45 (FIG. 8) is provided inside the opening 42. The table base 45 is provided below the moving plate 43. The moving plate 43 and the table base 45 are supported so as to move in the Y-axis direction by a Y-axis moving mechanism (not shown). Further, the table base 45 is supported so as to rotate about an axis in the Z-axis direction by a table rotation mechanism (not shown). The table base 45 can adjust the angle and magnitude of the inclination with respect to the device base 41 by an inclination adjustment mechanism (not shown).

[0042] As shown in FIG. 8, a plurality of bolt holes 46 are formed in the table base 45 at different positions in the circumferential direction. The number and arrangement of the bolt holes 46 correspond to the number and arrangement of the holes 19 in the chuck table 10. By placing the chuck table 10 on the table base 45 and screwing bolts (not shown) inserted through the holes 19 into the bolt holes 46, the chuck table 10 is fixed to the table base 45. In this fixed state, the chuck table 10 moves and rotates in the Y-axis direction together with the table base 45.

[0043] On the apparatus base 41, a column 48 is erected at a position adjacent to one end of the opening 42 in the Y-axis direction. A grinding mechanism 50 and a lifting mechanism 60 are supported by the column 48. By driving the lifting mechanism 60, the grinding mechanism 50 can be moved in the Z-axis direction to approach and separate from the chuck table 10.

[0044] The spindle unit 51 of the grinding mechanism 50 is, for example, an air spindle, and rotatably supports a spindle 52 via high-pressure air inside a casing. A mount 53 is connected to the tip (lower end) of the spindle 52, which is a shaft body extending in the Z-axis direction, and a grinding wheel 54 is mounted on the mount 53. A plurality of grinding wheels 55 are provided annularly on the lower surface side of the grinding wheel 54.

[0045] The lifting mechanism 60 includes a pair of parallel guide rails 61 arranged on the front side of the column 48 and extending in the Z-axis direction, a lifting table 62 slidably installed in the Z-axis direction with respect to the pair of guide rails 61, and a ball screw 63 extending in the Z-axis direction and screwed into a screwed portion (not shown) of the lifting table 62. By rotating the ball screw 63 by the driving force of a motor 64 connected to one end of the ball screw 63, the lifting table 62 moves in the Z-axis direction.

[0046] The grinding mechanism 50 is supported via a housing 65 provided on the front side of the elevating table 62. When the elevating table 62 is moved in the Z-axis direction by the elevating mechanism 60, the position of the grinding mechanism 50 in the Z-axis direction changes.

[0047] As shown in FIG. 8, in the grinding process, the chuck table 10 attached to the table base 45 is positioned below the grinding mechanism 50. The table base 45 and the chuck table 10 are adjusted to a predetermined inclination by an inclination adjusting mechanism (not shown). Then, the spindle 52 is rotated by the spindle unit 51, the grinding mechanism 50 is lowered by the elevating mechanism 60, and further the chuck table 10 is rotated by the table rotation mechanism, whereby the upper surfaces of the first porous member 30, the second porous member 31, the glass member 38, and the frame body 11 of the chuck table 10 are ground with the grinding wheel 55 to make the upper surface flat and form the first holding surface 32 and the second holding surface 33.

[0048] More specifically, as shown in FIG. 8, the first holding surface 32, the second holding surface 33, and the upper surface of the glass member 38 are formed on a conical surface having the center of the first holding surface 32 as the apex. Thereby, the upper surface of the chuck table 10 becomes a smooth surface where the glass member 38 neither protrudes nor recesses with respect to the first holding surface 32 and the second holding surface 33.

[0049] Through the above respective processes, the manufacturing method of the present embodiment is completed, and the chuck table 10 is completed. The completed chuck table 10 includes a first porous member 30 having a first holding surface 32, a second porous member 31 having a second holding surface 33, and a glass member 38 disposed between the first porous member 30 and the second porous member 31 and having the same upper surface as the first holding surface 32 and the second holding surface 33. The first porous member 30, the second porous member 31, and the frame body 11 are adhered by an adhesive member 36.

[0050] The completed chuck table 10 is subsequently attached to the table base 45 of the grinding device 40 and is used to hold a workpiece when the workpiece is ground by the grinding device 40.

[0051] As shown in FIG. 8, a first suction passage 70 and a second suction passage 71 are formed in the table base 45. With the chuck table 10 fixed to the table base 45, the first suction passage 23 of the chuck table 10 communicates with the first suction passage 70, and the second suction passage 24 of the chuck table 10 communicates with the second suction passage 71.

[0052] The first suction passage 70 is connected to a suction source 74 via an on-off valve 72, and the second suction passage 71 is connected to the suction source 74 via an on-off valve 73. When the suction source 74 is operated to open the on-off valve 72, the air in the first porous member 30 is sucked through the first suction passage 70, the first suction passage 23, and the first suction hole 20, and a suction force acts on the first holding surface 32 which is the upper surface thereof. When the suction source 74 is operated to open the on-off valve 73, the air in the second porous member 31 is sucked through the second suction passage 71, the second suction passage 24, and the suction groove 22 (second suction hole 21), and a suction force acts on the second holding surface 33 which is the upper surface thereof.

[0053] Since the first porous member 30 and the second porous member 31 are partitioned by an airtight glass member 38, air leakage does not occur between them, and suction forces can be individually applied to the first holding surface 32 and the second holding surface 33. With this configuration, the chuck table 10 can switch the shape of the suction surface corresponding to at least two workpieces having different areas or shapes. For example, a wafer with a small area such as a 6-inch wafer can be sucked and held by the first holding surface 32 of the first porous member 30, and a wafer with a large area such as a 12-inch wafer can be sucked and held by the second holding surface 33 of the second porous member 31 in combination with the first holding surface 32. Therefore, it is possible to form a suction surface 25 (holding surface) that matches the shape and size according to the purpose.

[0054] By grinding in the grinding process when manufacturing the chuck table 10, the upper surfaces of the first holding surface 32, the second holding surface 33, the glass member 38, and the frame body 11 are flush with each other. In particular, since the upper surface of the glass member 38 is formed flush with the first holding surface 32 and the second holding surface 33, there is no step at the location of the glass member 38. Therefore, when sucking and holding any of a plurality of types of workpieces having different areas or shapes, the workpiece can be brought into close contact with the suction surface 25 without gaps.

[0055] As described above, the chuck table 10 of the present embodiment includes a first porous member 30 having a first holding surface 32, a second porous member 31 having a second holding surface 33, and a glass member 38 disposed between the first porous member 30 and the second porous member 31, and is configured such that the first porous member 30, the second porous member 31, and the frame body 11 are adhered by an adhesive member 36.

[0056] In addition, in the method for manufacturing the chuck table 10 of the present embodiment, after adhering a single porous plate 13 to the frame body 11 in the adhesion process, a groove 28 is formed in the groove forming process, the glass member 38 is formed in the groove 28 in the filling process and the curing process, and the upper surfaces of the porous plate 13 (the first porous member 30 and the second porous member 31) are ground together with the glass member 38 in the grinding process.

[0057] According to the above chuck table 10 and its manufacturing method, compared with the conventional universal chuck table having a structure and manufacturing method in which a plurality of porous plates having a desired shape are individually manufactured and then attached to the frame body, the man-hours for manufacturing are reduced, and holding surfaces (the first holding surface 32 and the second holding surface 33) adapted to a plurality of desired workpiece shapes can be efficiently formed. As a result, the time required for manufacturing the chuck table 10 is shortened, and the productivity of the chuck table 10 is improved.

[0058] The glass member 38 disposed between the first porous member 30 and the second porous member 31 on the chuck table 10 has a higher hardness than a resin barrier member and is more likely to ensure strength. Due to the high hardness of the glass member 38, when grinding the upper surface of the porous plate 13 together with the glass member 38 in the grinding process, there is no possibility that the glass member 38 is excessively ground and dents are formed on the first holding surface 32 and the second holding surface 33. Further, when using the completed chuck table 10, even if a strong load is applied from above when grinding the workpiece, there is no possibility that the portion of the glass member 38 is compressed and dented or damaged.

[0059] In addition, the glass member 38 has an advantage that it is less likely to adhere machining chips to the first holding surface 32 and the second holding surface 33 when ground in the grinding process compared to a resin barrier member.

[0060] In addition, when the hardness (strength) of the porous plate 13 (the first porous member 30, the second porous member 31) and the hardness (strength) of the glass member 38 are significantly different, in the grinding process, the difference between the grinding load on the porous plate 13 and the grinding load on the glass member 38 becomes large, and it may be difficult to form the holding surface of the chuck table 10 with precise accuracy. For example, due to the difference in the grinding load of each part, there is a possibility that a dent is formed between the first porous member 30 and the second porous member 31 and the glass member 38 after the grinding process.

[0061] In order to prevent such problems, granular aggregates are added to the second glass paste 37 that forms the glass member 38 to adjust the grinding load, and the grinding load when grinding the glass member 38 (the cured second glass paste 37) and the porous plate 13 (the first porous member 30, the second porous member 31) with the grinding wheel 55 may be made substantially the same. The aggregates added to the second glass paste 37 are, for example, granular bodies of the same material as the porous plate 13, or granular bodies of the same glass material as the glass powder contained in the second glass paste 37. By appropriately setting the material and particle size of these granular bodies, the grinding load of the glass member 38 can be adjusted.

[0062] Depending on whether the grinding load of the glass member 38 is relatively high or low compared to the grinding load of the porous plate 13, the aggregate to be added is selected. When the grinding load of the glass member 38 is relatively high, an aggregate with a material and particle size that has the effect of reducing the grinding load is added. When the grinding load of the glass member 38 is relatively low, an aggregate with a material and particle size that has the effect of increasing the grinding load is added.

[0063] In the chuck table 10 of the above embodiment, the first glass paste 35 that forms the adhesive member 36 and the second glass paste 37 that forms the glass member 38 are the same member (same material). By making the first glass paste 35 and the second glass paste 37 the same member, the cost required for material preparation can be reduced.

[0064] The state of the glass for obtaining the required adhesive performance in the adhesive member 36 and the state of the glass for obtaining the required barrier performance in the glass member 38 are different from each other. The formation of the glass member 38 in the curing process needs to be heated under the condition that the paste-like second glass paste 37 cures in the cooling process after heating at the second temperature. The formation of the adhesive member 36 in the adhesion process requires not only that the paste-like first glass paste 35 simply cures, but also that the adhesive member 36 has adhesiveness to adhere the first porous member 30, the second porous member 31, and the frame body 11 to each other, and thus it needs to be heated at a higher temperature (the first temperature).

[0065] Therefore, the first temperature in the adhesion process is set relatively high, and the second temperature in the curing process is set relatively low. However, the respective numerical values of the softening point and melting point of each of the glass pastes 35 and 37, and the respective numerical values of the first temperature and the second temperature in the above embodiment are merely examples, and each temperature is not limited to the above numerical examples. At least, the first temperature only needs to satisfy the condition of being equal to or higher than the softening point and equal to or lower than the melting point of the first glass paste 35, and the second temperature only needs to satisfy the condition of being lower than the first temperature.

[0066] When the first glass paste 35 and the second glass paste 37 are the same member, there is an advantage that it becomes easy to manage the first temperature for forming the adhesive member 36 in the adhesion step and the second temperature for forming the glass member 38 in the curing step. For example, in order to prevent the adhesive member 36 formed in the adhesion step from being denatured by excessive heating in the subsequent curing step and the adhesiveness from being lowered, the second temperature may simply be set lower than the first temperature. Further, since the second temperature can be arbitrarily set within a range that does not reach the first temperature, the glass member 38 formed in the curing step can be surely cured without insufficient heating. Therefore, the adhesion performance of the adhesive member 36 and the barrier performance of the glass member 38 can be surely obtained by easy temperature control.

[0067] However, it is also possible to make the first glass paste 35 and the second glass paste 37 different members (different materials). For example, the glass powder contained in the first glass paste 35 and the glass powder contained in the second glass paste 37 may be a plurality of types of glass having different softening points and melting points.

[0068] In this case, it is preferable to select the one in which the softening point of the glass powder contained in the second glass paste 37 is lower than the softening point of the glass powder contained in the first glass paste 35. For example, when the same one as the above embodiment (melting point: 1000 ° C, softening point: 800 ° C) is used as the first glass paste 35, the second glass paste 37 uses the one having a softening point of the glass powder of 550 ° C.

[0069] If, contrary to the above setting, the softening point of the glass powder contained in the second glass paste 37 is higher than the softening point of the glass powder contained in the first glass paste 35, the second temperature for heating the second glass paste 37 in the curing step may be equal to or higher than the first temperature for heating the first glass paste 35 in the adhesion step. Then, the adhesive member 36 may be excessively heated in the curing step, which may affect the adhesion performance. Further, since the second temperature required for the curing step is high, the energy consumption for heating increases, resulting in a large amount of cost and time.

[0070] On the other hand, if the softening point of the glass powder contained in the second glass paste 37 (e.g., 550°C) is lower than the softening point of the glass powder contained in the first glass paste 35 (e.g., 800°C), the second temperature can be surely set lower than the first temperature, and the adhesive member 36 and the glass member 38 can be formed under good processing conditions at low cost.

[0071] Also, as an element other than temperature, in order to optimize the effect of heating, the length of the heating time in the adhesion step and the length of the heating time in the curing step may be made different.

[0072] Also, as an element other than temperature, the range of the particle size of the glass powder contained in the first glass paste 35 and the range of the particle size of the glass powder contained in the second glass paste 37 may be made different. When the ranges of the particle sizes of the glass powder are different, it affects the ease of occurrence of the state change of each of the glass pastes 35 and 37 when heated. Therefore, by appropriately selecting the range of the particle size of the glass powder in combination with temperature control, it is possible to control the manifestation of adhesiveness in the adhesion step and the ease of curing in the curing step.

[0073] The above embodiment is applied when the chuck table 10 holds two types of circular workpieces having different diameters, and the disk-shaped first porous member 30 and the annular second porous member 31 are provided. However, the shapes and sizes of the first porous member 30 and the second porous member 31 are merely examples, and the shapes and sizes of the plurality of porous members provided in the chuck table may be different from those of the above embodiment. For example, it can also be applied to a chuck table that holds a rectangular workpiece or a chuck table that holds a partial circular workpiece having an orientation flat formed thereon.

[0074] According to the shape and size of the workpiece held by the chuck table, the shape of the groove formed in the porous plate 13 in the groove forming step is set. When holding two types of circular workpieces with different diameters, it is preferable to form an annular groove 28 in the porous plate 13 as in the above embodiment. When holding a rectangular workpiece or a partial circular workpiece with an orientation flat formed, the groove formed in the porous plate 13 in the groove forming step preferably has a straight portion at least partially.

[0075] Also, although the chuck table 10 of the above embodiment divides the porous plate 13 into two, namely the first porous member 30 and the second porous member 31, it can also be applied to a chuck table divided into three or more holding surfaces in order to hold three or more types of workpieces with different shapes and sizes. In this case, by increasing the number of barrier members corresponding to the glass member 38 of the above embodiment or making the barrier members cross each other partially, the number of divided holding surfaces can be increased. That is, the two first porous members 30 and the second porous member 31 in the above embodiment are merely examples of the minimum number, and the case where the chuck table includes three or more porous members such as a third porous member and a fourth porous member is not excluded.

[0076] In the above embodiment, in the grinding step, the first holding surface 32, the second holding surface 33, and the glass member 38 are ground to be on the same conical surface, but the holding surface of the chuck table (the upper surface of the porous plate) is not limited to a conical surface and may be a flat surface. For example, in a cutting device that performs cutting on a workpiece or a polishing device that performs polishing on a workpiece, a chuck table with a flat holding surface is used. The present invention is also applicable to such a chuck table and its manufacturing method. Specifically, after performing the grinding step with a grinding device, the completed chuck table is removed from the grinding device and attached to the table base of a cutting device or a polishing device for use.

[0077] Note that the embodiments of the present invention are not limited to the above embodiments and modified examples, and various changes, substitutions, and modifications may be made without departing from the spirit of the technical idea of the present invention. Furthermore, if the technical idea of the present invention can be realized in another way by the progress of technology or another derived technology, that method may be used for implementation. Therefore, the scope of the claims covers all embodiments that can be included within the scope of the technical idea of the present invention.

Industrial Applicability

[0078] As described above, according to the chuck table of the present invention and its manufacturing method, a chuck table that sucks and holds at least two workpieces having different areas or shapes can be manufactured in a short time, and the operating efficiency and operating costs of a processing apparatus equipped with the chuck table can be reduced.

Explanation of Signs

[0079] 10: Chuck table 11: Frame 12: Recess 13: Porous plate 15: Base 16: Protrusion 17: Bottom surface (inner surface of recess) 18: Side surface (inner surface of recess) 20: First suction hole 21: Second suction hole 22: Suction groove 23: First suction path 24: Second suction path 25: Suction surface 26: Lower surface (outer surface of porous plate) 27: Outer peripheral surface (outer surface of porous plate) 28: Groove 30: First porous member 31: Second porous member 32: First holding surface 33: Second holding surface 35: First glass paste 36: Adhesive member 37: Second glass paste 38: Glass member 40: Grinding device 41: Device base 45: Table base 50: Grinding mechanism 52: Spindle 54: Grinding wheel 55: Grinding stone 60: Lifting mechanism 70: First suction path 71: Second suction path 72: On-off valve 73: On-off valve 74: Suction source

Claims

1. A chuck table capable of switching the shape of a suction surface for sucking and holding at least two workpieces having different areas or shapes, respectively, comprising: a first porous member having a first holding surface, a second porous member having a second holding surface, a glass member disposed between the first porous member and the second porous member, and a frame body having a recess for accommodating the first porous member, the second porous member, and the glass member, and the first porous member, the second porous member, and the frame body are adhered by an adhesive member.

2. The chuck table according to claim 1, wherein the glass member and the adhesive member are formed of the same member.

3. A method for manufacturing a chuck table capable of switching the shape of a suction surface for sucking and holding at least two workpieces having different areas or shapes, respectively, comprising: placing the upper surface of a porous plate in a recess of a frame body in an exposed state, applying a first glass paste to the inner surface of the recess and the outer surface of the porous plate, and heating at a first temperature to adhere the frame body and the porous plate; after the adhesion step, forming a groove reaching from the upper surface of the porous plate to the bottom surface of the recess; a filling step of filling the groove with a second glass paste; a curing step of heating the second glass paste at a second temperature lower than the first temperature to cure the second glass paste and form a glass member; a grinding step of grinding the upper surface with a grinding stone to form the suction surface; A method for manufacturing a chuck table.

4. The method for manufacturing a chuck table according to claim 3, wherein the first glass paste and the second glass paste are the same member.

5. The method for manufacturing a chuck table according to claim 3 or claim 4, wherein granular aggregate is added to the second glass paste to make the grinding load the same when grinding the cured second glass paste and the porous plate with a grinding stone.

Images